Problem with query_posts

Hi,

I’ve got problems with query_posts in my index.php page on my personal template.

I want to display my personnal post type called “pub” (advert in french), my categoryname : “accueil” (home), and who has the tag “carre”.

I’ve got 2 another loop before who dispay the 4 firsts posts, in all category, then the 4 firts posts another personal post type.
That’s not working, this is my code :

<div id="publicite">
<?php
query_posts("post_type=pub&category_name=accueil&tag=carre");
if (have_posts()) :
while (have_posts()) : the_post();
the_content();
endwhile;
endif;
?>
</div>

Thanks a lot.